Block-signaling system



R. l. HEWETT AND S M. WARD, Jn.

' BLOCK SIGNALING SYSTEM.

APPLXCATION FILED APR. l7, I917.

Patented Dec. 21, 1920.

2 SHEETS-SHEET 1.

ATTORNEY g R. J. HEWETT AND S M. WARD, JR.

BLOCK SIGNALING SYSTEM APPLICATION FILED APR. 17, 1917.

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24 .A IS 0T mm 8 M r n n w ow P unites STATES PATENT OFFICE.

ROBERT J. I-IEVIETT, OF WESTFIELD, NEW JERSEY, AND S. MORTIMER WARD,33., OF WOODMERE, NEW YORK, ASSIGNOR-S TO JOHN TEFFTE CLARKE, OF NEWYORK, N. Y.

BLOCK-SIGNALiNG svsrnrr.

Specification of Letters Patent.

Patented Dec. 21, 1920.

Application filed April 17, 1917. Serial No. 162,624.

To all whom it may concern:

Be it known that we, ROBERT J. Hnwn'rr and S. MoRTIMER l/VARD, J12, bothcitizens oi. the United States, and residents, respeo tively, ofVVesti-leld, Union county, New Jersey, and Woodmere, Nassau county, NewYork, have invented certain new and useful Improvements inBlock-Signaling Systems, of which the following is a specification.

Our invention relates to block signaling systems, and it is especiallyuseful in block signaling systems for governing tratfic in both.directions along a single track.

One of the objects of the invention is to provide a durable and eficientsignaling system of the above type.

Another object of the invention is to provide means automaticallycontrolled by a car which overruns a dangef signal by entering the blockwhen said signal is set, for preventing the cartrom clearing the signalin returning from the block, and means for restoring the said firstmeans to its normal position when the car leaves the block.

The invention, in one aspect, may be considered as an improvement in thesignaling system shown and described in U. 5. Patent No. 12%1062,granted to S. M. Ward, J12, on September 25, 1917, for electricsignaling system, since the present invention is well adapted for use inconnection with said system. But it is to be understood that thisinvention is in no way limited to the system shown and described in saidlast-mentioned patent, nor to any otherparticular type of blocksignaling system, since it is applicable to various types of signalingsystems in which danger signals are subject to be overrun by cars, andwhere it is not desired to have the car disturb the signals by itsreturn from the block. In said prior sys term, means were provided forpreventing a car which overran a signal from disturbing the signals ofthe block in overrunning them, and said means taken in combination withthe means that we have provided for preventing the car in leaving; theblock under the danger signal from disturbing it, prevents the car fromdisturbing the signals in entering or leaving the block.

The invention consists in the novel features and combinationshereinafter scribed in their preferred forms, and the invention isparticularly pointed out in the claims.

Further objects and advantages of the invention will more fully appearfrom the following description taken in connection with the accompanyingdrawings illustrating the preferred embodiments of the invention adaptedto the signaling system shown in the said lVard application, and inwhichi Figure 1 is a diagrammatic view of a signaling system embodyingthe preferred form of the invention for controlling traflio in bothdirections along a single track where the trolley-actuated or engagingcontacts are placed in the turn-outs from the single track; and i Fig. 2shows the preferred form of the invention where trolley contacts areplaced within the stretch of single track known as the block.

Referring to the drawings (Fig. 1which shows the system with its partsin their proper positions with one car in the block, traveling west), 1is an incandescent lamp in a local circuit 7 which remains closed'allthe time. 2 is a target or red transparency which is normally held aloftby solenoid 3 but which is allowed to drop over the lamp 2 when thesolenoid is dee'nergized. The solenoid is placed in a local circuit 4whi h is held normally closed by a relay 6 of relatively highresistance, T he target carries a contact to bridge contacts 11 forshort cirsuiting resistance 9 when the target is released. to cover lamp1.

A is a step-by-step controller comprising a ratchet wheel 12which'carries a finger 15 for engaging switch 17 and a pin 16 forengaging a proje tion on the frame '(not shown) to limit the movement ofthe wheel. The switch 17, having three arms for con trolling circuitshereinafter to be mentioned, is pivoted on a shaft and held in either ofits operating positions by a spring 18. A pawl :20 for advancing thecontroller is operated by magnet-'19, which is energized through cir uit21 and controlled by relay 6 and the trolley contact 89. A magnet 28which is energized through circuit 29 operates pawl 30 to restore thecontroller; the circuit 29 being controlled at contacts 31, 33 and 19;contacts being controlled by a stick relily i i 38 is an incandescentlamp (in this case green) situated in a local circuit 10 which iscontrolledby relay 51 of relatively low resistance, 2'. 6., having arelatively few turns and switch 24. This lamp constitutes the cautionsignal or return indication and may be replacedbya target and lampsimilar to the one above mentioned for circuit 4, in which case at leastone white light will always be displayed to direct the motormansattention in the direction of the signal stand.

The circuit 21 and magnet 19 for advancing the controller, are energizedby the engagement of elongated contact 39 by the trolleycontact, thiscontact 39 being placed above the incoming branch of the turn-out;

' 40 and continues through wire 44, contacts 45. wire 46, contacts 47controlled by relay 48, thence to the trolley wire. From this it will beseen that the stick relay 41 cannot be energized by an incoming carunless the contacts 43 are closed by the energizetion of relay 6, and itwill further be ob- 1 served that when the stick relay 41 is acturelays41 and 48 are ared and closes its stick circuit at contacts 45; thecircuit remains closed until broken at contacts 47 controlled by therelay 48. The relay 48 is energized by the engagement .of elongatedcontact 50 by a car passing out of the block, thus opening the stickcircuit. deenergizing the stick relay and again closing contacts 33 tothe controller-clearing circuit. Duplicate trolley contacts and placedat the other end of the block. r

The high resistance relays 6 and 6', i. 6., relays'with a relativelylarge number of turns,are designedso that either of them will attractits core when energized with one of the resistances 9 0119' in circuit,and yet .willbe capable of remaining in circuit tor any length of tune,w1th the resistance cut out, without undue heating. To accomplish thisit is only necessary to use a slightly larger wire than usual in windingthe relay coil. 5 r r 'The relatively low resistance relays 51 and 51are so designed that neither of them I will attract its core to closeits contacts'54 or,- 54" when it is energized with one of theres1stances9or [9' 1n c1rcu1t;but upon the resistance being brigded therelay will-bee:

come energized sufiiciently to attract its core and close contacts 54 or54'. The resistances 9 and 9' are such that when out in and out of thecircuit they will varythe current in line 34 by a considerablepercentage of its normal value, thus insuring the proper operation ofthe relays at all times.

A conductor 34 extends along the block through which the signals areset, and it has similar trolley and ground connections at each end. Thetrolley branch at A includes contacts 35, relay 6, and resistance 9; theground branch including contacts 37 and relay 51, while the branch atBincludes similar apparatus.

A second conductor 32 extends along the block having duplicate trolleyand ground connections at each end. The trolley connection at A includescontacts 33 and wire '53; the ground branch including contacts 31, wire29 and magnet 28.

As stated, Fig. 1 shows the condition of the system after a car hasentered the block at the left and is traveling west, and its operationis as follows:

A car entering the block at the left engages elongated contact 39, thusbridging said contact to the trolley Wire and closing the followingcircuit: contact 39, wire 21, contact 23, continuing along wire 21 tomagnet 19, thence to ground. IVIagnet 19 being energized will operatepawl 20 to turn disk 12 one step in an anti-clockwise direction, causingfinger 15 to engage the right-hand edge of switch 17 and throw the sameto close contacts 31 and 37 and open contacts 35. Aidetent, not shown,holds the disk in its operated position and spring 18 holds switch 17 inits operated position. The closing of contacts 37 completes a circuitfrom ground at the left (station A) through relay 51, contacts 37, wire36, conductor 34, cont-acts 35 at B, wire 8, relay 6, resistance 9 totrolley wire. The closing of this circuit energizes relay 6, causingitto attract its core and open circuit 4 and 21'. The opening of circuit4' deenergizes solenoid 3', causing the red disk 2' to fall over (thenormally burning) lamp 1 to indicate danger. Upon the signal being set,resistance 9- is bridged by a contact carried by the disk and thecurrent in conductor 34 is increased to' energize relay 51 at the leftsufiiciently to cause it to close contacts 54. It contacts 25 have beenpreviously closed by the deenergization of magnet 19, the closing ofcontacts 54 will light the green lamp to indicate a clear block ahead,but if the contacts 25-have not beenclosed, the lamp will be lightedupon the closing of these contacts, as the pawl returns to its normalposition. a

The closing of contacts 31 completes a circuit from ground at A throughsolenoid 28, wire 29, contacts31, conductor 32, contacts 33 at B toelongated contact 49'; and

another circuit which branches near contacts 31 at A, and leads tocontacts 33 at A and wire 53 to elongated contact 49. From this it willbe seen that a car in the block may energize solenoid 28 to returncontroller disk 12 and operate switch 17 to clear'the signals when itleaves the block at either end, at which time it will engage eithercontact 49 or 49 to energize said magnet 28 by either completing acircuit from trolley wire at B through wire 53, contacts 33, line wire32 and contact 31 at A to said magnet; or from contact 49 at A throughwire 53, contacts 33 and 31 to said magnet. The contacts 31 at B beingnormally open, prevent the operation of the controller at B when the carpasses out of the block.

The opening of the circuit of relay 6 at contacts 35 at A when the carentered, prevents any possible setting. of the danger signal at that endby a car accidentally run ning into the block at B. Likewise, the re lay6 at B having opened circuits 4' at its back contacts 55, and havingopened circuit 21 to controller magnet 19, prevents any possible settingof the safety signal 38' at' that end. The contacts 37 in the circuit ofrelay 51 are also open, thus preventing the closure of contacts 54 inthe circuit 10 of the signal 38. It will thus be seen that a caroverrunning a danger signal and entering at that end of the block canneither give nor receive a signal while the other car remains in theblock, nor can it clear the signals already set by a car in the block.This feature of preventing the car in overrunning the danger signal,from affecting the signals that have already been set, was pro vided forand formed a part of the subject matter of the said Ward application.But in that application, the provision made for permitting the car toback out of the block without affecting the signals, was depend ent upona certain act of the motorman of the car; that is to say, in said systemprovision was made in the signaling system whereby the car could backout of the block without affecting the signals, provided the motormanoperated a certain switch, as for example, his controller, to break thecircuit from his trolley contact to ground while the trolley contactwasin engagement with the signal-controlling elongated contact. short,the said system did not, automatically and independently of some act onthe part of the motorman, prevent the set signals from beinginterfer'red with, and maintain the signals in their desired position,when the overrunning car left the block.

It is very important to positively prevent such an overrunning car fromaffecting these signals, regardless of any voluntary act on the part ofthe motorinam In other words, it is important to provide meansautomatically operated responsive to the entrance of the overru'nningcar into the block, to prevent said car from affecting the signals whenit backs out of or returns from the block. The provision of such meansis the principal object of this invention, and in the form of theinvention shown this contingency is taken care of in the followingmanner. Supposing, now, that a car is in the block in Fig. 1, with theparts of the signaling system in the position shown. If a carapproaching the block from the right should for any reason overrun thedanger signal, as for example by approaching the block at too high arate of speed, or having the signal thrown suddenly in front of it sothat it is not brought to a stop before it passes the signal, the car inentering the block, will engage elongated contact 39', thus closing acircuit from said contact through wire 21, branch wire 40', stick relay41', wire 42', through contacts 43 (now closed by reason of theenergization of relay 6), thence to ground. The energization of thiscircuit energizes the stick relay, opening contacts 33' and closingcontacts 45' in the stick circuit of said relay, which circuitcontinuing from contacts 45 extends along wire 46', through contacts 47(now closed), to the trolley wire. When the car leaves the elongatedcontact 39 in entering the block, the stick circuit maintains the relayenergized and maintains contacts 33 open, thus maintaining the clearingline circuit 32 open. When the car backs out of the block it passes outthrough the lower turnout, thus energizing elongated contact 49', theenergization of which fails to actuate either controller, due to thefact that contacts 33' are now open. The car next engages elongatedcontact 50, energizing relay 48 and breaking the stick relay stickcircuit, permitting the relay to again close c(' ntacts 33- to completethe clearing circuit 32 to contact 49', ready for the next car to passout of the block.

It will thus be seen that this contingency is automatically and readilytaken care of by means responsive to the movement of the car into andout of the block. In another patent granted to the said Ward onSeptember 25, 1917, for electric signaling system, No. 1241063, meansare provided for preventing a car which has overrun a danger signal fromaffecting the already-set signals in backing out of the block, withoutany act on the part of the motorman not necessary to bringing the carout of the block. But said means was dependent upon the operation of atrack switch at the time that the car left the block, and is thereforeimpracticable in systems where track switches are not-provided at theextremities of the single track block sections to be controlled by thesignals, and in by far the majorityof cases, conditions of tratlic aresuch that only turn-outs, in the strictest sense of the Word, areprovided without the use of track switches.

It is extremely diflicult to cause any two magnets connected in separatecircuits, to be operated so simultaneously that one will not close itscontact ahead of the other to energize or deenergize any circuit orcircuits that would be energized or denergized by one but not affectedby the simultaneous operation of both; and in practice, such acontingency would scarcely, if ever, arise; and likewise, the conditonwhere the setting and clearing magnets 19 and 28 of the controller aresimultaneously energized by cars entering and leaving the block, wouldscarcely if ever arise. But in the event that it should arise, thecontroller will be properly operated responsive to both magnets inproper sequence, by adapting the provisions for overcoming this troubledescribed and claimed in said Ward Patent No. 1,241,062. This provisionconsists in making one of the relays stronger than the other, and inproviding the actuated pawl of each relay with an instantaneous release,so that the instant that one relay is energized and has moved thecontroller, the pawl is freed from contact with the controller, so thatthe controller is free to be moved responsive to the pawl of the otherrelay. Since the details of such a device are fully set forth in saidapplication, and form no part of the present invention, it isunnecessary to describe it in detail here.

In some installations, it is desirable to place the trolley contacts ortrolley-engaging switches, as the case may be, within the block, at eachend thereof, instead of just outside of the block and above theturn-outs, and in Fig. 2 we have-shown a modification of our inventionillustrating the preferred form of the same for an installation of thiskind. In this instance, the ontrollers, the line circuits andsignal'circuits' proper are identical to those shown and described. Theonly differences pertain to the trolley-engaged contacts and thecircuits and relays at these contacts which govern the'setting andclearing circuits of the controllers and the circuit of the stick relay,so that only these will be described. i

In Fig. 2, the same indicating numerals as were used in Fig. 1, areagain used to indicate like parts and circuits. Referring to Fig. 2, therelay 48 in circuit 52 is energized by the bridging of the trolley wireand elongated contact 50 by the trolley contact, for the purpose ofopening contacts 47 to de energize the stick relay stick circuit 46, ashas been previously explained in connection with Fig. 1. Relay 60 islocated in circuit 61 from elongated contact 62 and the relay isprovided with an upper contact member 63"adapted to close contact 64 inwire 65 leading from the trolley wire to wire 21, for the purpose ofenergizing the controlleractuating magnet 19 when a car enters theblock. This relay 60 is also provided with a lower contact member 66adapted to close contact 67 in wire 40 leading to the stick relay, forthe purpose .of energizing the same when a car overruns a danger signal,as will hereinafter be explained. The relay 60 has its movable or switchmember suitably mechanically interlocked with relay 69 through theintermediation of a bar 71 ful crumed at '7 2 and pivotally connected ateach end to the movable members of the said relays 60 and 69. In orderto maintain the relay switch members in their neutral position as shown,the bar is provided with suitable springs 73 which immediately snap orreturn the switch members to the position shown whenever the relays areboth denergized. The relay 69 is located in a circuit from elongatedcontact 70, and when energized, its upper switch member 74 closescontact 75 in a branch 76 from wire 65 to close the circuit throughcontacts 33 and wire 29 to controller magnet 28 for clearing thesignals. The lower switch member'66 of relay 60 is connected throughconductor 68 to the elongated contact 70, and one of the contacts 78engaged by the lower contact member 77 of relay 69. is connected withelongated con tact 62 by wire 79. The purpose of thesecross-connections, so to speak, will be more readily understood inexplaining the operation of the system.

Assume now, that with no cars in the block, a car approaches the blockfrom the east. As the trolley contact engages elongated contact 50, itenergizes relay 48 which simply breaks the stick relay stick circuitwhich is already broken. As the trolley contact engages "elongatedcontact 62 "to bridge the same to the trolley wire, a circuit is closedthrough wire 61 and relay 60, thus closing contacts 64 and 67 Theclosing of contact 64 energizes the circuitv previously traced tocontrol actuating magnet 19' to operate the controller and set the sig-'nals. The closing of contact 67 in the circuit of the stick relay'41 hasno effect because said circuit is open at contacts 43 controlled byrelay 6. The engagement of the lower contact member 66'of relay 60 withone 'of the contacts 67 also closes a circuit from said elongatedcontact 62 through said contact member 66,- wire 68, and elongatedcontact 7 0, through relay 69. But the closing of this circuit and'theenergization of the relay 69 will not actuate the switch member of saidrelay, due to the fact that the switch member of relay 60 had alreadybeen moved to its upper position and the switch of relay 69 to its lowerposition, in which position the switch members'will be held as long asboth relays are maintained energized. The adjacent ends of contacts 70and 62 sufliciently overlap so that the trolley or other travelingconductor engages one before it leaves the other, and as the trolleycontact engages elongated contact 70, bridging the same to the trolleywire, the energization of relay 60 is maintained through wire 68 andswitch member 66 to said relay, and the switch members of the relaysmaintain their normal position until the trolley contact leaveselongated contact 70, whereupon both relays 60 and 69 are deenergizedand the said relay switch members are again moved to their positionsshown. It will be noted that if it were not for the cross-connectingwire 68 which maintained relay 6O energized during the time that relay69 was energized, the relay 69 would have closed contact 75, thuscompleting a circuit to the restoring magnet 28 and clearing the signaljust set. It will thus be seen that in entering the block the car setsthe proper signals.

lVhen the car reaches the other end of the block, its contact engageselongated contact 70, energizing relay 69 to close contacts 75 and 78'.The closing of contact 75' completes the circuit from the trolley wirethrough wire said contact 75, wire 7 6, and contacts 33, thence alongrestoring line wire 32, contacts 31 at A to the clearing magnet 28 torestore the signals. The closing of contact 78 below the relay closed acircuit to interlocked relay 60, as follows: from the elongated contactthrough contact 7 8, wire 7 9, elongated contact 62 and wire 61',through said relay 60. But the energization of this circuit isineffective due to the fact that relay 69 was first energized holdingits contacts closed and holding the contacts of relay 60 open. As thecar passes to elongated con tact 62, relay 69 remains energized throughthe cross-connecting wire 79, thus preventing the closing of the lowercontacts '67 of relay 60, which, if they were closed,

would close the circuit from the elongated contact 62 through wire 40 tothe stick relay, causing it to open its contacts 33', which openingmight follow so quickly on the closing of the clearing circuit atcontact 7 5' that the duration of energization of the clearing circuitwould not be sufficient to permit magnet 28 to actuate the controllerfor clearing the signals. As the trolley contact bridges the trolleywire and elongated contact 50, it energizes relay 48, causing it to opencontacts 47; but without effect, since the stick relay stick circuit isalready open at the stick relay. It will thus be seen that the car inleaving the block clears the signal in proper manner.

Supposing, now, that with the danger signals 2 set and the other partsof the sig- 65 naling system as shown in Fig. 2, a car should overrunthe danger signal at the these contacts and controller magnet 28, isalready broken at 23. The closing of contact 67, however, energizes thecircuit through wire 40, stick relay 41, wire 42, contacts 43, toground, thus energizing the stick relay, which in turn closes its upperor stick contacts 45,,completing, the stick circuit through wire 46 andcontacts 47', to ground (provided the denergization of relay 48 haspermitted the closing of the contacts 47 by this time). If relay 48 hasnot had time to drop its contact member to close these contacts in thestick circuit, the stick relay 41 will, nevertheless, be maintained inits energized position when the trolley contact engages contact 70 byreason of the cross-connecting wire 68', which maintains the followingcircuit to the stick relay: Elongated contact 70, Wire 68, switch member66, wire 40 to the stick relay. This cross-connection provides ampletime for the closing of the stick circuit by relay 48 before the stickrelay actuating circuit is finally open. The engagement of the elongatedcontact 70 by the car energizes the other interlocked relay 69, butwithout effect, since the energization of relay 60 is maintained untilthe car leaves elongated contact 70.

When the car, having overrun the danger signal, returns from the block,it first engages elongated contact 70', energizing relay 69 and closingupper contact and lower contact 78. The closing of the upper contact 75is ineffective because the stick relay has opened the clearing circuitat contacts 33. The closing of the lower contact 78 closes a circuitthrough wire 79 to the other interlocked relay 60. But this isineffective, due to the prior energization of relay 69 which holds itscontacts closed and the contacts of relay 60 open. As the trolleycontact engages wire 62, the energization of relay 69 is maintainedthrough wire 7 9, and the closing of the contacts of relay 60 thusprevented (the closing of 75' due to. the fact that the circuit,including which, however, at this moment would do that the car in theblock traveling from east to west may clear the signals on leaving theblock.

While we have described our invention with particularity and detail inthe two embodiments thereof shown, for the purpose of illustrating itsoperation and advantages, it will be obvious to those skilled in theart, afterunderstanding our invention, that I various modifications andimprovements maybe made therein and the particular embodiment of theinvention changed to suit diii'erentsignaling systems, without departingfrom the spirit or scope of our invention, and we aim to cover all suchmodifications and do not wish to be understood as limiting ourselvesother than as indicated in the appended claims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is

1. In a block signaling system for con trolling traffic along a track inboth directions, the combination with a .danger signal to be displayedat one end or the block and apermissive signal to be displayed at theother end of the block, means including a step-by-step controller forsetting said signals responsive to the entrance of a car in the block atone end, means including a circuit and a contact energized by a carleaving the block at the danger signal end for restoring the controllerstep bystep, and means operated responsive to a car in over running thedanger signal to prevent the clearing of the signals by the return ofsaid car from the block.

2. In a block signaling system, the combination with a signal at one endof a block, and means for effecting the setting and clearing of thesignal respectively, responsive to a car entering" the block at theoppo' site end from the signal and leaving the block at said signal end,of a stick relay operatively related to the signal-clearing means, andmeans including the control circuits for said stick relay foroperatingthe same responsive to a car overrunning said signal byentering the block at the signal end, to render the signal-clearingmeans inoperative to clear the signal when said last car returns fromthe block.

3. In a block signaling system, the comsaid last circuit for controllingsaid circuitand stick relay responsive to a car overrunning the signalby entering the block at the signal end, to effect the operation of therelay and render the signal-clearing circuit inoperative to clear thesignal when said last car returns from the block.

, 4. In ablock signaling system, the combination with a signal at oneend of the block, means for controlling the setting of the signalresponsive to a car entering the block at the opposite end from thesignal, and means including a circuit with a contact at said signal endof the block for controlling the clearing er said signal responsive to acar leaving the block at said signal end, of means including astick'relay having a contact controlling the signal-clearing circuit torender same inoperative at times to clear the signal, a circuit for thestick relay having a contact closed while the signal is set, and havinganother contact for closing the relay circuit to cause the relay to openthe signal-clearing circuit, responsive to a car overrunning the signalby entering the block at the signal end, so as to prevent the clearingof the signal when said last car returns from the block.

5. In a block signaling system for controlling traffic along a track inboth directions, the combination with a signal at one end of the block,means for controlling the setting of the signal responsive to a carentering the block at the opposite end from the signal, and meansincluding a circuit with a contact at said signal end of the block forcontrolling the clearing of said signal responsive to a car leaving theblock at said signal end, of means including a stick relay operativelyrelated to said signal-clearing circuit to render same inoperative attimes to clear the signal, and means controlling said relay responsiveto the overrunning of the signal by a car entering the block at thesignal end, to

prevent the clearing of the signal by the return from the block of saidlast car.

6. In a block signaling system for controlling trafiic along a track inboth directions, the combination with a signal at one end of the blockto be displayed to indicate danger and means for effecting the settingand clearing of the signal respectively, responsive to a car enteringthe block at the opposite end from the'signal and leaving the block atsaid signal end, of means operated in the setting of said signal toprevent said signal being cleared responsive to a car entering the blockat the signal end, a stick relay operatively related to thesignal-clearing means to render the same inoperative at times to clearthe signal, and means controlling said relay responsive to theoverrunning of the signal by a car entering the block at the signal end,to prevent the operation of the clearing means to clear the signal whensaid last car returns from the block.

7. In a block signaling system for controlling traffic along a track inboth directions, the combination with a signal at one end of the blockto be displayed to indicate danger and means for effecting the settingand clearing of the signal respectively, responsive to a car enteringthe block at the opposite end from the signal and leaving the block atsaid signal end, of means operated responsive to the signal settingmeans to prevent said signal being cleared responsive to a car enteringthe block at the signal end, a stick relay operatively related to thesignal-clearing means to render the same inoperative at times to clearthe signal, means for energizing said relay responsive to theoverrunning of the signal by a car entering the block at the signal end,to prevent the operation of the clearing means to clear the signal whensaid last car returns from the block, and means for deenergizing thestick relay responsive to the return of said car from the block.

8. In a block signaling system for controlling traflic along a track inboth directions, the combination with a signal to' be displayed at oneend of the block responsive to a car entering at the opposite end of theblock and to be cleared responsive to the car leaving at the signal endof the block, means including a step-by-step controller likewiseactuated. by cars entering and leaving the block, to permit cars toenter or leave the block while another is in the block, withoutderanging the signals, and means including control circuits foradvancing and restoring the controller, of a stick relay having acontact controlling the controller-restoring circuit to render thecircuit inoperative to restore the controller at times, a circuit forsaid stick relay having contacts closed when said signal is set, andmeans for energizing the stick relay circuit responsive to a carentering the block, whereby, while the danger signal is displayed, if acar overruns said signal by entering the block, it will be preventedfrom clearing the signal in returning from the block.

9. In a block signaling system for controlling trafiic along a track inboth directions, the combination with a danger signal to be displayed atone end of the block and a permissive signal to be displayed at theother end of the block, means including a step-by-step controller forsetting said signals responsive to the entrance of a car in the block atone end, means including a circuit and a contact energized by a carleaving the block at the danger signal end for restoring the controllerstep by step responsive to cars leaving the block at said last end, ofastick relay for opening and closing the controller-restoring circuit, acircuit for the stick relay having contacts adapted to be closed whilethe danger signal is displayed,

said stick relay circuit having means whereby it is energized responsiveto the overrunning of the signal by a car entering the block at thedanger signal end, to open the controller-restoring circuit and preventthe operation of the controller responsive to the return from the blockof said last car, and means for deenergizing said stick relay responsiveto the return of said car from the block, whereby the restoring circuitis again closed;

10. In a block signaling system for controlling trafiic along a track inboth directions, the combination of a danger signal to be displayed atone end of the block and a permissive signal to be displayed at theother end of the block, means including a step-by-step controller forsetting said signals responsive to the entrance of a car in the block atone end, means including a circuit and a contact energized by a carleaving the block at the danger signal end for restoring the controllerstep by step, means for preventing the clearing of the signals by a caroverrunning the danger signal, means operated responsive to the car inoverrunning the danger signal, to prevent the clearing of the signals bythe return of said last car, and means for automatically restoring saidlast means to its former position when the car leaves the block.

In testimony whereof, we have signed our names to this s ecification.

R BERT J. nnwnrr. s. MORTIMER WARD, JR.

